1. Field of the Invention
The present invention relates to a hydraulic crusher attached to a distal section of an arm of a working machine such as a hydraulic excavator, and used for demolition etc. of a structure.
2. Description of the Related Art
Hitherto, demolition of a concrete structure etc. has been performed by using a large-scale breaker or a hydraulic crusher attached to a distal section of an arm of a hydraulic excavator. In particular, when demolition is performed in, for example, an urban area, a hydraulic crusher is frequently used because the hydraulic crusher has measures to reduce dust, vibration, and noise as compared with the large-scale breaker.
A hydraulic crusher typically includes a pair of crushing arms that crush an object to be crushed, a crusher body a distal section of which supports the crushing arms in an openable and closable manner around pivots, and a pair of hydraulic cylinders coupled to proximal section of the crusher body and to the crushing arms respectively rotatably around pivots. Hydraulic hoses that connect ports at the proximal section of the crusher body with ports at proximal sections of the hydraulic cylinders are formed between the distal section and the proximal section of the crusher body to prevent the hydraulic hoses from being damaged because of collision with scattering crushed pieces. Also, major parts of the hydraulic hoses are housed in a hollow portion surrounded by cover plates (for example, see Japanese Unexamined Patent Application Publication Nos. 2004-68393 and 2008-18364).
In this hydraulic cylinder, the crushing arms are opened when piston rods of the hydraulic cylinders are accommodated in cylinder bodies, and the crushing arms are closed when the piston rods protrude from the cylinder bodies. The concrete structure etc. gripped by the open crushing arms is crushed by the crushing arms when the crushing arms are closed.
However, in the hydraulic crusher of the related art, the hydraulic crusher attached to the distal section of the arm of the working machine is very compact. When a port of the crusher body is directly connected to a port of the hydraulic cylinder through a single hydraulic hose, the hydraulic hose is bent with a small bend radius in the hollow portion of the crusher body. The hydraulic hose may be damaged.
Also, since the hydraulic hose is housed in the hollow portion of the crusher body in a constrained manner, it may be difficult to replace a damaged hydraulic hose with new one.
In light of the situations, a hydraulic crusher shown in FIG. 8 may be conceived. The hydraulic crusher effectively uses the hollow portion of the crusher body. For the convenience of viewing, FIG. 8 does not illustrate a frame or a part of a cover member which define a crusher body 105.
In this hydraulic crusher 101, hydraulic hoses that connect the crusher body 105 with hydraulic cylinders 103 are divided into first hydraulic hoses 107, 117, 127, and 137 which are connected to ports (not shown) of the crusher body 105, and second hydraulic hoses 109, 119, 129, and 139 which are connected to ports (not shown) of the hydraulic cylinders 103. Also, a joint block 131 is provided in a distal section of a hollow portion 165 of the crusher body 105. Distal sections of the first hydraulic hoses 107, 117, 127, and 137 are connected to distal sections of the second hydraulic hoses 109, 119, 129, and 139.
With this hydraulic crusher 101, the hydraulic hoses that connect the crusher body 105 with the hydraulic cylinders 103 are divided into the first hydraulic hoses 107, 117, 127, and 137 and the second hydraulic hoses 109, 119, 129, and 139. Thus, the first and second hydraulic hoses 107, 117, 127, and 137 and 109, 119, 129, and 139 each can be easily replaced with new one. In addition, the distal sections of the first hydraulic hoses 107, 117, 127, and 137 are connected to the distal sections of the second hydraulic hoses 109, 119, 129, and 139 through the joint block 131. Thus, the first and second hydraulic hoses 107, 117, 127, and 137 and 109, 119, 129, and 139 do not have to be bent with a small bend radius. The first and second hydraulic hoses 107, 117, 127, and 137 and 109, 119, 129, and 139 can be prevented from being damaged.
Since the opposite ends of the first hydraulic hoses 107, 117, 127, and 137 are fixed, the first hydraulic hoses 107, 117, 127, and 137 are not moved although the crushing arms 111 are opened and closed. Thus, as long as the length of the second hydraulic hoses 109, 119, 129, and 139 is a length that prevents the second hydraulic hoses 109, 119, 129, and 139 from interfering with the first hydraulic hoses 107, 117, 127, and 137, more particularly, a length that prevents the second hydraulic hoses 109, 119, 129, and 139 from being loosened and curved even when the crushing arms 111 are closed, the first and second hydraulic hoses 107, 117, 127, and 137, and 109, 119, 129, and 139 can be prevented from being rubbed on one another and hence being damaged.
However, in the hydraulic crusher 101 having the joint block 131 at the distal section of the crusher body 105, the other problems may come up as follows. The length of the second hydraulic hoses 109, 119, 129, and 139 is limited so as not to be loosened and curved even when the crushing arms 111 are closed. Thus, when the crushing arms 111 are closed, that is, when the hydraulic cylinders 103 are opened to be widened toward the distal side, the second hydraulic hoses 109, 119, 129, and 139 are pulled and become tensed between the hydraulic cylinders 103 and the joint block 131. The second hydraulic hoses 109, 119, 129, and 139 tend to be damaged.
The second hydraulic hoses 109, 119, 129, and 139 only have small flexibility because the opposite ends of the second hydraulic hoses 109, 119, 129, and 139 are fixed. When the hydraulic cylinders 103 are contracted (when the cylinder bodies 113 are moved toward the proximal side so as to accommodate the piston rods, not shown), crushed pieces or the like may be stacked between the cylinder bodies 113 and the second hydraulic hoses 109, 119, 129, and 139. The second hydraulic hoses 109, 119, 129, and 139 may be damaged.